According to this interactive chart from Time magazine, journalists polled are slightly happier than butchers, mail deliverers and bus drivers.
I know, I'd think it would not be that bad to be a butcher. Just as depressing is that more insurance salespeople said they were happy in their work than journos. Interestingly, PR people are only slightly happier than journalists.
Among the happiest were priests, firefighters, architects and actors. So when I'm hanging out with actors and architects, now I know for sure that I'm the least "happy" one in the bunch. (Perhaps I should investigate a career change more seriously. I do like preaching to the choir...)